Pingjun Zhang

Solubility and Seeded Metastable Zone width of functional sugar L-arabinose

L-arabinose is widely used in food, medicine, chemistry, and biology fields; however, solubility and seeded metastable zone width (MSZW) of L-arabinose have not been reported in the literature. In this paper, solubility and MSZW of L-arabinose in aqueous solution were determined. Solubility of L-arabinose was measured in the range of 20-68 °C by a conventional equilibrium solubility method and quantitation was determined using the ion chromatography technique. Seeded MSZW was determined in the range of 51-73% by the calorimetric method. The effect of two salts (potassium chloride and calcium chloride) on the solubility and MSZW of L-arabinose were also evaluated. Results showed that both potassium chloride and calcium chloride increased the solubility of L-arabinose, and this increase was intensified with temperature rise. The MSZW of L-arabinose was not constant but a spread. Potassium chloride increased the MSZW of L-arabinose. However, the effect of calcium chloride on MSZW of L-arabinose was concentration dependent. Conclusion: the L-arabinose solubility increased with the increase in temperature, and both potassium chloride and calcium chloride increased the solubility of L-arabinose in aqueous solution. The seeded MSZW of L-arabinose is not a constant; it increases in the presence of potassium chloride and varies with the change in calcium chloride concentration.

The effect of spray drying on sucrose-glycine caramel powder preparation.

BACKGROUND Caramel is used as food colorant in many parts of the world. However, there have been no studies investigating the effects of spray drying on sucrose and glycine solutions. In this study, model sucrose and glycine solutions at different pH levels (pH 4, 3, 2 and 1) were treated with different inlet air temperatures (160, 180, 200, 220 and 240 °C) for durations of 50 s in the spray drying process. RESULTS With increasing inlet temperatures and decreasing pH, the morphology of the caramel agglomerates tended to be more scattered; however, the solubility of the caramel decreased. With increasing inlet temperature, the glycine and sucrose contents decreased but the fructose and glucose contents increased. CONCLUSION The content of the intermediate products, browning intensity and amount of 5-hydroxymethyl-2-furaldehyde (HMF) increased with increasing inlet temperature and decreasing pH. Therefore, the amount of sucrose degradation and the change in pH can be used to evaluate caramel properties in the spray drying process.